Vesicles and red blood cells in shear flow

Area of Science:

• Fluid dynamics
• Soft matter physics
• Biophysics

Background:

• Individual soft particles, including drops, lipid vesicles, and red blood cells, are fundamental components in various biological and industrial systems.
• Their behavior under external forces, particularly shear flow, is critical for understanding processes like blood circulation and microfluidic applications.
• The mechanical properties of these particles significantly influence their deformation and trajectory in flow.

Purpose of the Study:

• To elucidate the similarities and specificities in the behavior of individual soft particles (drops, lipid vesicles, red blood cells) under shear flow.
• To investigate the non-trivial dependence of particle motion on their intrinsic mechanical properties.
• To analyze the impact of boundaries, specifically walls with and without attractive interactions, on particle dynamics from a biological viewpoint.

Main Methods:

• Computational fluid dynamics simulations were employed to model particle behavior.
• Analysis of particle trajectories and deformation under controlled shear flow conditions.
• Examination of particle-wall interactions, including attractive forces, in a shear flow environment.

Main Results:

• Particle motion in shear flow is intricately linked to their viscoelastic properties.
• The presence of a wall alters particle trajectories, with attractive interactions leading to distinct behaviors.
• Red blood cells, lipid vesicles, and drops display both universal and unique responses to shear flow and confinement.

Conclusions:

• The mechanical properties of soft particles are key determinants of their behavior in shear flow.
• Wall interactions, especially attractive forces, introduce significant modifications to particle dynamics, relevant for biological contexts.
• This study provides insights into the fundamental physics governing soft particle suspensions and their interactions with boundaries.